Friends said the girl, whom they named as Shereka Marsh, was sociable, good at sport and had wanted to study business.
Police were called to the shooting at a house in Eastway in Hackney, east London, shortly before 4pm on Saturday.
The London Ambulance Service and London’s Air Ambulance attended, but the 15-year-old girl was pronounced dead at the scene. A post-mortem examination found she died from a gunshot wound to the neck.
Two 16-year-old boys and a 15-year-old boy were arrested nearby and taken to an east London police station, where they were in custody yesterday, a Scotland Yard spokesman said. He added that a gun was recovered from the house.
Mourners visited the scene to lay flowers and leave messages of condolence.
Chainelle Jennings, 16, a friend and schoolmate of the victim, was among a group of eight of the girl’s friends who gathered opposite the house where the shooting happened.
“She was a nice bubbly girl and she loved to party, loved shopping. She was the kind of girl that you would have to fall in love with,” she said. “She liked PE. Her favourite subject was history. She was good at sports. She wanted to study business.”
The teenager added: “She lived with her mum, her dad was in Jamaica. They just had each other, just them two and they lived together. She cherished her mum. Her mum was very protective.”
Chainelle said she had heard Shereka was accidentally shot in the neck and bled to death.
Drew Percival, 16, a friend of the victim, said: “She had a good mindset, she was very funny. She was more of the business type. She liked her clothes, it was all designer. She was very sociable, a lot of friends.
“She was good at sports. She was always that person who was making everyone laugh. Sleepovers, party time and food – she used to eat. She even used to tell me what to wear. She had a range of things she wanted to do. She was an only child. We tried to speak to her mum but she wasn’t in.
“Some of the teachers came to the Homerton hospital last night. They were trying to calm everyone else.”
She said Shereka had been in a relationship since January.
Krista Brown, an ambassador for the National Apprenticeship Service, whose son Shad Brown knows Shereka and the teenagers who were arrested, said: “It’s a tragic situation for both sides of the coin. And that’s what should be noted, it really is. Nice girl, just a local girl. This is a local community.
“They’re our kids, what people fail to realise is that this is our kids’ reality. They were all local to here.
“She went to my niece’s school, Urswick School. Pretty girl, nice, hard-working. From what I’ve seen on Facebook popular, friends with everybody. The boys involved were as well.
“My son knows the boys involved, he knows all the kids involved.”
She added: “We spend 20 years of our life protecting our children and hoping this doesn’t happen to them.”
Tributes have also been paid to the victim on Twitter and Facebook. A Facebook page called “R.I.P. Shereka” has more than 10,000 likes.
Azmina Bhamji commented on the page: “The good die young. Another angel up in heaven, she’s up there smiling at everyone, rest in peace princess.”
Jessica Leonard posted: “Rest in peace beautiful Shereka you will be missed loads and we all miss you loads already.”